Routers process information packets, typically, in the order received, so that the order of packets exiting a router is the same as the order of packets entering the router. Therefore, the incoming packet rate must be maintained throughout processing of the packet, so that the packet flow does not fall behind, resulting in queuing and latency of packets. There are typically many flow paths from input to output of a router. However, in a worst-case scenario all of the packets coming in through a particular port are routed to go to a common destination, all at the same QOS level, all through the same tributary. Packet forwarding at the input of a router must be able to handle that worst-case packet rate for an individual flow.
The rate at which packets flow through a system, for example a OC192c rate of 10 gigabits per second where an individual packet can be on the order of 40-50 nanoseconds in duration, must be maintained in processing these packets. In the industry today, packet forwarding engines are available that can handle a OC48c rate, which is 2.5 gigabits per second. However, the industry is not yet mature enough to provide packet forwarding engines that can handle packets at 10 gigabits per second. Therefore, solutions are needed that enable processing OC192c packet flow rates with existing packet forwarding engines that currently have less capability than a conventional OC48c or OC192c rate. Typically, individual packet forwarding engines, even for the lower OC48c rate, require many processing elements all working in parallel in a chip set or in an individual chip to handle a packet input rate at 2.5 gigabits per second. To handle packets at that rate typically requires multiple parallel processing elements. The individual packet forwarding engine is responsible for maintaining the order of the packets coming into the packet forwarding engine to make sure that packets are coming out in the same order. However, if multiple packet forwarding engines are ganged together to have a higher rate, the combined individual packet forwarding engines cannot maintain packet ordering.